It is 25 Messidor, year VI of the French Revolution. Arrayed before Napol?on Bonaparte's army is a stupendous sight: A crescent-shaped arc of over seven thousand Mameluke cavalry festooned with pistols and scimitars, draped in rich, colorful silken robes, extending from the Nile River right around their line. Behind them are some ten thousand fellahin, armed with clubs and cudgels. Suddenly, the Mamelukes let out a collective cry from seventeen thousand...